The men's marathon was a track and field athletics event held as part of the athletics at the 1912 Summer Olympics programme. It was the fifth appearance of the event, which is one of 12 athletics events to have been held at every Summer Olympics. The distance used was 40.2 kilometres, nearly 2 full kilometres shorter than that used in 1908 and since 1924. The competition was held on Sunday, July 14, 1912.

Sixty-eight runners from 19 nations competed.

With conditions described as "very hot", only half of the competitors finished.[1]

Records[]

These were the standing world and Olympic records (in hours) prior to the 1912 Summer Olympics.